Pectic activities from<i>Fusarium oxysporum</i>f. sp.<i>melonis</i>: Purification and characterization of an exopolygalacturonase

Abstract

Fusarium oxysporum f. sp. melonis produced an extracellular enzymic mixture with high pectic activities, (at least an exopolygalacturonase, an endopolygalacturonase and two lyases) in a medium with glucose and pectin as carbon sources. An exopolygalacturonase from this crude enzyme preparation was purified 23.8 times by Sephadex G-200 and ion-exchange HPLC. It had a Km of 6 mM, a Mr of 58 000, a pI of 6.4, optimum pH of 5 and was stable in the 3.5–6.5 pH range. This enzyme preferentially hydrolysed polygalacturonic acid, showing only 5% activity on pectin, and did not exhibit the activity of an endoenzyme.